This invention relates to a cover or door construction and more particularly to a cover or door construction which is periodically exposed to high temperatures.
The invention is particularly applicable to use in conjunction with coke oven openings and will be described with particular reference thereto. However, it will be appreciated by those skilled in the art that the invention has broader applications and may be used in other environments where a cover or door which is exposed to elevated temperatures must resist or adapt to heat induced warpage which would otherwise prevent proper sealing.
Coke oven is a term of art employed for the large ovens which are used to produce coke or coke by-products from coal. While there are a number of types and styles of coke ovens, they typically have a substantial vertical heighth and depth in relation to the width and, in many respects, resemble a very large closet. Normally, a plurality of the individual ovens are located in a side by side relationship to form what is commonly termed an oven battery in order that a high volume of coke and coke by-products may be made at one location. In many instances, the height of these ovens is well over 10' and virtually the entire front face thereof may be selectively opened and closed by means of a coke oven door.
In addition to the very large coke oven doors, these ovens also include so-called charging holes and gooseneck openings. These holes or openings are much smaller than the basic coke oven doors with the charging holes being located adjacent the coke oven top and utilized for purposes of charging the coke oven prior to the coking operation. The gooseneck openings are disposed outside the ovens adjacent the bottom areas thereof for purposes of collecting tars, pitch, residue and other by-products of the coking operation. The charging openings typically communicate directly with the associated coke oven whereas the gooseneck openings typically communicate with large tubes or pipes which, in turn, communicate directly with coke ovens. The gooseneck openings are, therefore, in indirect communication with the associated coke oven. During a coking operation, all of the charging and gooseneck openings must be covered or closed in order to prevent any heat and pollution loss from the ovens as well as air admission thereinto.
In prior coke ovens, the charging and/or gooseneck opening covers or doors have been constructed from cast iron and were thought to be the best means in which to avoid undesired warpage during coking operations. Warpage is a significant problem due to high temperatures, e.g., 2000.degree. F. and above, inside the ovens which act on these covers. When warpage occurs, the original close fitting or sealing relationships between the covers and openings is disturbed so that the aforementioned heat and pollution problems occur. Such circumstances are undesirable from both environmental and operational points of view.
While prior charging and gooseneck opening covers have variously utilized special sealing structures, such structures have not eliminated the sealing problems when warpage occurs. The principal problem with prior cast iron covers of this type has been diagnosed as failure to warp evenly when subjected to coking operation temperatures. This problem is magnified for those prior charging and gooseneck opening covers which do not include any special sealing structure. Indeed, in some instances, it was necessary to place refractory brick or material over the cover or door adjacent the edge thereof in order to reduce the emission problem.
The subject invention is directed toward apparatus adapted for use with coke oven charging and gooseneck openings which overcomes the above mentioned problems and others and provides a new and improved cover construction which is simple to manufacture, readily adapted to use on virtually all types of charging and gooseneck openings on different types and styles of coke oven designs, and provides a structure which facilitates continuous sealing around the periphery of an associated charging or gooseneck opening during coking operations.